1
|
Abstract
Voltage-gated sodium channels (VGSCs) are critical in generation and conduction of electrical signals in multiple excitable tissues. Natural toxins, produced by animal, plant, and microorganisms, target VGSCs through diverse strategies developed over millions of years of evolutions. Studying of the diverse interaction between VGSC and VGSC-targeting toxins has been contributing to the increasing understanding of molecular structure and function, pharmacology, and drug development potential of VGSCs. This chapter aims to summarize some of the current views on the VGSC-toxin interaction based on the established receptor sites of VGSC for natural toxins.
Collapse
Affiliation(s)
- Yonghua Ji
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, China.
| |
Collapse
|
2
|
Xiao YH, Zunic-Kosi A, Zhang LW, Prentice TR, McElfresh JS, Chinta SP, Zou YF, Millar JG. Male adaptations to minimize sexual cannibalism during reproduction in the funnel-web spider Hololena curta. INSECT SCIENCE 2015; 22:840-852. [PMID: 26033974 DOI: 10.1111/1744-7917.12243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/29/2015] [Indexed: 06/04/2023]
Abstract
Males of many spider species risk being attacked and cannibalized while searching for, courting, and mating with conspecific females. However, there are exceptions. We show that the funnel-web spider, Hololena curta, has 3 adaptations that minimize risk to males during courtship and mating, and enhance reproductive success. First, males detected chemical or tactile signals associated with webs of virgin females, and differentiated them from webs of mated females, enabling males to increase encounter rates with virgin females and avoid aggressive mated females. Second, males produced stereotyped vibrational signals during courting which induced female quiescence and suppressed female aggression. Third, when touched by males, sexually receptive females entered a cataleptic state, allowing males to safely approach and copulate. Because males can mate multiple times and the sex ratio in natural populations of H. curta is female biased, overall reproductive output is likely increased by males of this species avoiding sexual cannibalism.
Collapse
Affiliation(s)
- Yong-Hong Xiao
- College of Life Sciences, Jinggangshan University, Ji'an, Jiangxi, 343009, China
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Alenka Zunic-Kosi
- Department of Entomology, National Institute of Biology, Ljubljana, SI-1000, Slovenia
| | - Long-Wa Zhang
- Department of Entomology, University of California, Riverside, CA, 92521, USA
- Anhui Provincial Key Laboratory of Microbial Control, Anhui Agricultural University, Hefei, Anhui, 230036, China
| | - Thomas R Prentice
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - J Steven McElfresh
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Satya P Chinta
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Yun-Fan Zou
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Jocelyn G Millar
- Department of Entomology, University of California, Riverside, CA, 92521, USA
| |
Collapse
|
3
|
Zhang YY, Huang Y, He QZ, Luo J, Zhu L, Lu SS, Liu JY, Huang PF, Zeng XZ, Liang SP. Structural and Functional Diversity of Peptide Toxins from Tarantula Haplopelma hainanum (Ornithoctonus hainana) Venom Revealed by Transcriptomic, Peptidomic, and Patch Clamp Approaches. J Biol Chem 2015; 290:14192-207. [PMID: 25770214 DOI: 10.1074/jbc.m114.635458] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Indexed: 11/06/2022] Open
Abstract
Spider venom is a complex mixture of bioactive peptides to subdue their prey. Early estimates suggested that over 400 venom peptides are produced per species. In order to investigate the mechanisms responsible for this impressive diversity, transcriptomics based on second generation high throughput sequencing was combined with peptidomic assays to characterize the venom of the tarantula Haplopelma hainanum. The genes expressed in the venom glands were identified, and the bioactivity of their protein products was analyzed using the patch clamp technique. A total of 1,136 potential toxin precursors were identified that clustered into 90 toxin groups, of which 72 were novel. The toxin peptides clustered into 20 cysteine scaffolds that included between 4 and 12 cysteines, and 14 of these groups were newly identified in this spider. Highly abundant toxin peptide transcripts were present and resulted from hypermutation and/or fragment insertion/deletion. In combination with variable post-translational modifications, this genetic variability explained how a limited set of genes can generate hundreds of toxin peptides in venom glands. Furthermore, the intraspecies venom variability illustrated the dynamic nature of spider venom and revealed how complex components work together to generate diverse bioactivities that facilitate adaptation to changing environments, types of prey, and milking regimes in captivity.
Collapse
Affiliation(s)
- Yi-Ya Zhang
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Yong Huang
- the State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dong-Da Street, Fengtai District, Beijing 100071, China
| | - Quan-Ze He
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Ji Luo
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Li Zhu
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Shan-Shan Lu
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Jin-Yan Liu
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Peng-Fei Huang
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Xiong-Zhi Zeng
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Song-Ping Liang
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| |
Collapse
|
4
|
A novel ICK peptide from the Loxosceles intermedia (brown spider) venom gland: Cloning, heterologous expression and immunological cross-reactivity approaches. Toxicon 2013; 71:147-58. [DOI: 10.1016/j.toxicon.2013.05.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/10/2013] [Accepted: 05/15/2013] [Indexed: 12/28/2022]
|
5
|
Abstract
Venomous animals use a highly complex cocktails of proteins, peptides and small molecules to subdue and kill their prey. As such, venoms represent highly valuable combinatorial peptide libraries, displaying an extensive range of pharmacological activities, honed by natural selection. Modern analytical technologies enable us to take full advantage of this vast pharmacological cornucopia in the hunt for novel drug leads. Spider venoms represent a resource of several million peptides, which selectively target specific subtypes of ion channels. Structure-function studies of spider toxins are leading not only to the discovery of novel molecules, but also to novel therapeutic routes for cardiovascular diseases, cancer, neuromuscular diseases, pain and to a variety of other pathological conditions. This review presents an overview of spider peptide toxins as candidates for therapeutics and focuses on their applications in the discovery of novel mechanisms of analgesia.
Collapse
Affiliation(s)
- Pierre Escoubas
- University of Nice - Sophia Antipolis, Institut de Pharmacologie Moléculaire et Cellulaire (IPMC) - CNRS UMR6097, 660 Route des Lucioles, 06560 Valbonne, France +33 04 93 95 77 35 ; +33 04 93 95 77 08 ;
| | | |
Collapse
|
6
|
Klint JK, Senff S, Rupasinghe DB, Er SY, Herzig V, Nicholson GM, King GF. Spider-venom peptides that target voltage-gated sodium channels: Pharmacological tools and potential therapeutic leads. Toxicon 2012; 60:478-91. [DOI: 10.1016/j.toxicon.2012.04.337] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 04/07/2012] [Indexed: 12/19/2022]
|
7
|
Schwartz EF, Mourão CBF, Moreira KG, Camargos TS, Mortari MR. Arthropod venoms: A vast arsenal of insecticidal neuropeptides. Biopolymers 2012. [DOI: 10.1002/bip.22100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
8
|
Windley MJ, Herzig V, Dziemborowicz SA, Hardy MC, King GF, Nicholson GM. Spider-venom peptides as bioinsecticides. Toxins (Basel) 2012; 4:191-227. [PMID: 22741062 PMCID: PMC3381931 DOI: 10.3390/toxins4030191] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/07/2012] [Accepted: 03/15/2012] [Indexed: 12/19/2022] Open
Abstract
Over 10,000 arthropod species are currently considered to be pest organisms. They are estimated to contribute to the destruction of ~14% of the world's annual crop production and transmit many pathogens. Presently, arthropod pests of agricultural and health significance are controlled predominantly through the use of chemical insecticides. Unfortunately, the widespread use of these agrochemicals has resulted in genetic selection pressure that has led to the development of insecticide-resistant arthropods, as well as concerns over human health and the environment. Bioinsecticides represent a new generation of insecticides that utilise organisms or their derivatives (e.g., transgenic plants, recombinant baculoviruses, toxin-fusion proteins and peptidomimetics) and show promise as environmentally-friendly alternatives to conventional agrochemicals. Spider-venom peptides are now being investigated as potential sources of bioinsecticides. With an estimated 100,000 species, spiders are one of the most successful arthropod predators. Their venom has proven to be a rich source of hyperstable insecticidal mini-proteins that cause insect paralysis or lethality through the modulation of ion channels, receptors and enzymes. Many newly characterized insecticidal spider toxins target novel sites in insects. Here we review the structure and pharmacology of these toxins and discuss the potential of this vast peptide library for the discovery of novel bioinsecticides.
Collapse
Affiliation(s)
- Monique J. Windley
- Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, Broadway NSW 2007, Australia; (M.J.W.); (S.A.D.)
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia; (V.H.); (M.C.H.)
| | - Sławomir A. Dziemborowicz
- Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, Broadway NSW 2007, Australia; (M.J.W.); (S.A.D.)
| | - Margaret C. Hardy
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia; (V.H.); (M.C.H.)
| | - Glenn F. King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia; (V.H.); (M.C.H.)
| | - Graham M. Nicholson
- Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, Broadway NSW 2007, Australia; (M.J.W.); (S.A.D.)
| |
Collapse
|
9
|
Peptide neurotoxins that affect voltage-gated calcium channels: a close-up on ω-agatoxins. Toxins (Basel) 2011; 3:17-42. [PMID: 22069688 PMCID: PMC3210452 DOI: 10.3390/toxins3010017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 12/23/2010] [Accepted: 12/30/2010] [Indexed: 12/02/2022] Open
Abstract
Peptide neurotoxins found in animal venoms have gained great interest in the field of neurotransmission. As they are high affinity ligands for calcium, potassium and sodium channels, they have become useful tools for studying channel structure and activity. Peptide neurotoxins represent the clinical potential of ion-channel modulators across several therapeutic fields, especially in developing new strategies for treatment of ion channel-related diseases. The aim of this review is to overview the latest updates in the domain of peptide neurotoxins that affect voltage-gated calcium channels, with a special focus on ω-agatoxins.
Collapse
|
10
|
Billen B, Vassilevski A, Nikolsky A, Debaveye S, Tytgat J, Grishin E. Unique bell-shaped voltage-dependent modulation of Na+ channel gating by novel insect-selective toxins from the spider Agelena orientalis. J Biol Chem 2010; 285:18545-54. [PMID: 20385552 DOI: 10.1074/jbc.m110.125211] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Spider venoms provide a highly valuable source of peptide toxins that act on a wide diversity of membrane-bound receptors and ion channels. In this work, we report isolation, biochemical analysis, and pharmacological characterization of a novel family of spider peptide toxins, designated beta/delta-agatoxins. These toxins consist of 36-38 amino acid residues and originate from the venom of the agelenid funnel-web spider Agelena orientalis. The presented toxins show considerable amino acid sequence similarity to other known toxins such as mu-agatoxins, curtatoxins, and delta-palutoxins-IT from the related spiders Agelenopsis aperta, Hololena curta, and Paracoelotes luctuosus. beta/delta-Agatoxins modulate the insect Na(V) channel (DmNa(V)1/tipE) in a unique manner, with both the activation and inactivation processes being affected. The voltage dependence of activation is shifted toward more hyperpolarized potentials (analogous to site 4 toxins) and a non-inactivating persistent Na(+) current is induced (site 3-like action). Interestingly, both effects take place in a voltage-dependent manner, producing a bell-shaped curve between -80 and 0 mV, and they are absent in mammalian Na(V) channels. To the best of our knowledge, this is the first detailed report of peptide toxins with such a peculiar pharmacological behavior, clearly indicating that traditional classification of toxins according to their binding sites may not be as exclusive as previously assumed.
Collapse
Affiliation(s)
- Bert Billen
- Laboratory of Toxicology, University of Leuven, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, B-3000 Leuven, Belgium
| | | | | | | | | | | |
Collapse
|
11
|
|
12
|
|
13
|
Cordeiro MDN, Richardson M, Gilroy J, Figueiredo SGD, Beirão PSL, Diniz CR. Properties of the Venom from the South American ‘‘Armed'’ Spider Phoneutria Nigriventer (Keyserling, 1891). ACTA ACUST UNITED AC 2008. [DOI: 10.3109/15569549509019466] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
14
|
De Lima ME, Figueiredo SG, Pimenta AMC, Santos DM, Borges MH, Cordeiro MN, Richardson M, Oliveira LC, Stankiewicz M, Pelhate M. Peptides of arachnid venoms with insecticidal activity targeting sodium channels. Comp Biochem Physiol C Toxicol Pharmacol 2007; 146:264-279. [PMID: 17218159 DOI: 10.1016/j.cbpc.2006.10.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 10/19/2006] [Accepted: 10/21/2006] [Indexed: 12/18/2022]
Abstract
Arachnids have a venom apparatus and secrete a complex chemical mixture of low molecular mass organic molecules, enzymes and polypeptide neurotoxins designed to paralyze or kill their prey. Most of these toxins are specific for membrane voltage-gated sodium channels, although some may also target calcium or potassium channels and other membrane receptors. Scorpions and spiders have provided the greatest number of the neurotoxins studied so far, for which, a good number of primary and 3D structures have been obtained. Structural features, comprising a folding that determines a similar spatial distribution of charged and hydrophobic side chains of specific amino acids, are strikingly common among the toxins from spider and scorpion venoms. Such similarities are, in turn, the key feature to target and bind these proteins to ionic channels. The search for new insecticidal compounds, as well as the study of their modes of action, constitutes a current approach to rationally design novel insecticides. This goal tends to be more relevant if the resistance to the conventional chemical products is considered. A promising alternative seems to be the biotechnological approach using toxin-expressing recombinant baculovirus. Spider and scorpion toxins having insecticidal activity are reviewed here considering their structures, toxicities and action mechanisms in sodium channels of excitable membranes.
Collapse
Affiliation(s)
- M E De Lima
- Lab. Venenos e Toxinas Animais, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil; Núcleo de Biomoléculas - Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil.
| | - S G Figueiredo
- Centro de Ciências Fisiológicas, CBM - Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - A M C Pimenta
- Lab. Venenos e Toxinas Animais, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil; Núcleo de Biomoléculas - Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil
| | - D M Santos
- Lab. Venenos e Toxinas Animais, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil; Núcleo de Biomoléculas - Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil
| | - M H Borges
- Lab. Venenos e Toxinas Animais, Universidade Federal de Minas Gerais, 31.270-901, Belo Horizonte, MG, Brasil; Centro de Pesquisa Prof. Carlos R. Diniz, Fundação Ezequiel Dias, Belo Horizonte, MG, Brasil
| | - M N Cordeiro
- Centro de Pesquisa Prof. Carlos R. Diniz, Fundação Ezequiel Dias, Belo Horizonte, MG, Brasil
| | - M Richardson
- Centro de Pesquisa Prof. Carlos R. Diniz, Fundação Ezequiel Dias, Belo Horizonte, MG, Brasil
| | - L C Oliveira
- Departamento de Farmácia Bioquímica - Universidade Federal dos Vales do Jequitinhonha e Mucuri, 39100-000, Diamantina, MG, Brasil
| | - M Stankiewicz
- Laboratory of Biophysics - Institute of General and Molecular Biology, N. Copernicus University, 87-100, Torun, Poland
| | - M Pelhate
- Lab. Récepteurs et Canaux Ioniques Membranaires, Université d'Angers, 49045, Angers, France
| |
Collapse
|
15
|
Vieira LB, Pimenta AMC, Richardson M, Bemquerer MP, Reis HJ, Cruz JS, Gomez MV, Santoro MM, Ferreira-de-Oliveira R, Figueiredo SG, Snutch TP, Cordeiro MN. Leftward shift in the voltage-dependence for Ca2+ currents activation induced by a new toxin from Phoneutria reidyi (Aranae, Ctenidae) venom. Cell Mol Neurobiol 2006; 27:129-46. [PMID: 17151945 DOI: 10.1007/s10571-006-9123-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Accepted: 09/27/2006] [Indexed: 11/26/2022]
Abstract
Various neurotoxins have been described from the venom of the Brazilian spider Phoneutria nigriventer, but little is known about the venoms of the other species of this genus. In the present work, we describe the purification and some structural and pharmacological features of a new toxin (PRTx3-7) from Phoneutria reidyi that causes flaccid paralysis in mice. The observed molecular mass (4627.26 Da) was in accordance with the calculated mass for the amidated form of the amino acid sequence (4627.08 Da). The presence of an alpha-amidated C-terminus was confirmed by MS/MS analysis of the C-terminal peptide, isolated after enzymatic digestion of the native protein with Glu-C endoproteinase. The purified protein was injected (intracerebro-ventricular) into mice at dose levels of 5 microg/mouse causing immediate agitation and clockwise gyration, followed by the gradual development of general flaccid paralysis. PRTx3-7 at 1 microM inhibited by 20% the KCl-induced increase on [Ca2+]i in rat brain synaptosomes. The HEK cells permanently expressing L, N, P/Q and R HVA Ca2+ channels were also used to better characterize the pharmacological features of PRTx3-7. To our surprise, PRTx3-7 shifted the voltage-dependence for activation towards hyperpolarized membrane potentials for L (-4 mV), P/Q (-8 mV) and R (-5 mV) type Ca2+ currents. In addition, the new toxin also affected the steady state of inactivation of L-, N- and P/Q-type Ca2+ currents.
Collapse
Affiliation(s)
- L B Vieira
- Laboratório de Neurofarmacologia, Departamento de Farmacologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Richardson M, Pimenta AMC, Bemquerer MP, Santoro MM, Beirao PSL, Lima ME, Figueiredo SG, Bloch C, Vasconcelos EAR, Campos FAP, Gomes PC, Cordeiro MN. Comparison of the partial proteomes of the venoms of Brazilian spiders of the genus Phoneutria. Comp Biochem Physiol C Toxicol Pharmacol 2006; 142:173-187. [PMID: 16278100 DOI: 10.1016/j.cbpc.2005.09.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Revised: 09/02/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Abstract
The proteomes of the venoms of the Brazilian wandering "armed" spiders Phoneutria nigriventer, Phoneutria reidyi, and Phoneutria keyserlingi, were compared using two-dimensional gel electrophoresis. The venom components were also fractionated using a combination of preparative reverse phase HPLC on Vydac C4, analytical RP-HPLC on Vydac C8 and C18 and cation exchange FPLC on Resource S at pH 6.1 and 4.7, or anion exchange HPLC on Synchropak AX-300 at pH 8.6. The amino acid sequences of the native and S-pyridyl-ethylated proteins and peptides derived from them by enzymatic digestion and chemical cleavages were determined using a Shimadzu PPSQ-21(A) automated protein sequencer, and by MS/MS collision induced dissociations. To date nearly 400 peptides and proteins (1.2-27 kDa) have been isolated in a pure state and, of these, more than 100 have had their complete or partial amino acid sequences determined. These sequences demonstrate, as might be expected, that the venoms of P. reidyi and P. keyserlingi (Family: Ctenidae) both contain a similar range of isoforms of the neurotoxins as those previously isolated from P. nigriventer which are active on neuronal ion (Ca(2+), Na(+) and K(+)) channels and NMDA-type glutamate receptors. In addition two new families of small (3-4 kDa) toxins, some larger protein (>10 kDa) components, and two serine proteinases of the venom of P. nigriventer are described. These enzymes may be responsible for some of the post-translational modification observed in some of the venom components.
Collapse
Affiliation(s)
- M Richardson
- Fundacao Ezequiel Dias, Belo Horizonte, MG, Brazil.
| | - A M C Pimenta
- Department of Biochem. Immunol., University Fed. Minas Gerais, Belo Horizonte, MG, Brazil
| | - M P Bemquerer
- Department of Biochem. Immunol., University Fed. Minas Gerais, Belo Horizonte, MG, Brazil
| | - M M Santoro
- Department of Biochem. Immunol., University Fed. Minas Gerais, Belo Horizonte, MG, Brazil
| | - P S L Beirao
- Department of Biochem. Immunol., University Fed. Minas Gerais, Belo Horizonte, MG, Brazil
| | - M E Lima
- Department of Biochem. Immunol., University Fed. Minas Gerais, Belo Horizonte, MG, Brazil
| | - S G Figueiredo
- Department of Physiol. Sci., University Fed. Espirito Santo, Vitoria, ES, Brazil
| | - C Bloch
- CENARGEN/EMBRAPA, Brasilia, DF., Brazil
| | - E A R Vasconcelos
- Deparment of Biochem. Mol. Biol., University Fed. Ceara, Fortaleza, CE, Brazil
| | - F A P Campos
- Deparment of Biochem. Mol. Biol., University Fed. Ceara, Fortaleza, CE, Brazil
| | - P C Gomes
- Fundacao Ezequiel Dias, Belo Horizonte, MG, Brazil
| | - M N Cordeiro
- Fundacao Ezequiel Dias, Belo Horizonte, MG, Brazil
| |
Collapse
|
17
|
Down RE, Fitches EC, Wiles DP, Corti P, Bell HA, Gatehouse JA, Edwards JP. Insecticidal spider venom toxin fused to snowdrop lectin is toxic to the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae) and the rice brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae). PEST MANAGEMENT SCIENCE 2006; 62:77-85. [PMID: 16206236 DOI: 10.1002/ps.1119] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The SFI1/GNA fusion protein, comprising of snowdrop lectin (Galanthus nivalis agglutinin, GNA) fused to an insecticidal spider venom neurotoxin (Segestria florentina toxin 1, SFI1) was tested for toxicity against the rice brown planthopper Nilaparvata lugens (Stål) and the peach-potato aphid Myzus persicae (Sulzer) by incorporation into artificial diets. Significant effects on the mortality of N. lugens were observed, with 100% of the insects fed on the SFI1/GNA fusion protein diet dead by day 7. The survival of the aphid M. persicae was also reduced when fed on the SFI1/GNA fusion protein. After 14 days, only 49% of the aphids that were fed on the fusion protein were still alive compared with approximately 90% of the aphids fed on the control diet or on diet containing GNA only. The SFI1/GNA fusion protein also slowed the development of M. persicae, and the reproductive capacity of the aphids fed on the SFI1/GNA fusion protein was severely reduced. The ability of GNA to act as a carrier protein, and deliver the SFI1 neurotoxin to the haemolymph of N. lugens, following oral ingestion, was investigated. The successful delivery of intact SFI1/GNA fusion protein to the haemolymph of these insects was shown by western blotting. Haemolymph taken from the insects that were fed on the fusion protein contained two GNA-immunoreactive proteins of molecular weights corresponding to GNA and to the SFI1/GNA fusion protein.
Collapse
Affiliation(s)
- Rachel E Down
- Central Science Laboratory, Sand Hutton, York YO41 1LZ, UK.
| | | | | | | | | | | | | |
Collapse
|
18
|
Kozlov S, Grishin E. Classification of spider neurotoxins using structural motifs by primary structure features. Single residue distribution analysis and pattern analysis techniques. Toxicon 2005; 46:672-86. [PMID: 16169031 DOI: 10.1016/j.toxicon.2005.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 07/12/2005] [Accepted: 07/13/2005] [Indexed: 11/20/2022]
Abstract
In recent years the data on the novel structures of spider toxins have been greatly increasing. The sequence data should be classified. We introduced two primary structure analysis techniques-single residue distribution analysis (SRDA) and pattern analysis for classifying spider polypeptide toxins with molecular weight less than 10kDa. For multiple sequence alignment, we also introduced three novel sequence representation formats named as a simple record, motif record and a pattern record, which can be useful for large-scale analysis of structures. About 300 sequences of spider toxins were analyzed and nine primary structure motifs were identified. New classification of spider toxins was proposed on the basis of previously described principal structural motif (PSM) and extra structural motif (ESM) [Kozlov, S.A., Malyavka, A.A., McCutchen, B., Lu, A., Schepers, E., Herrmann, R., Grishin, E.V., 2005. A novel strategy for the identification of toxin-like structures in spider venom. Proteins 59 (1), 131-140]. Five main structural classes were revealed, and for putative ion channel inhibitors from the most numerous classes 1, 2, and 3, five-digital personal ID numbers were introduced. A reference table with simple, motif and pattern representation sequence formats was created for all analyzed structures.
Collapse
Affiliation(s)
- Sergey Kozlov
- Neuroreceptors and Neuroregulators Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya, 16/10, 117997 Moscow, Russian Federation.
| | | |
Collapse
|
19
|
Kozlov S, Malyavka A, McCutchen B, Lu A, Schepers E, Herrmann R, Grishin E. A novel strategy for the identification of toxinlike structures in spider venom. Proteins 2005; 59:131-40. [DOI: 10.1002/prot.20390] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
20
|
Vieira ALG, Moura MB, Babá EH, Chávez-Olórtegui C, Kalapothakis E, Castro IM. Molecular cloning of toxins expressed by the venom gland of Lasiodora sp. Toxicon 2004; 44:949-52. [PMID: 15530979 DOI: 10.1016/j.toxicon.2004.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Revised: 08/18/2004] [Accepted: 08/23/2004] [Indexed: 11/17/2022]
Abstract
The present work describes the identification of toxins expressed by the venom gland of the spider Lasiodora sp. The toxins LTx1, LTx2 and LTx3 were identified by the screening of a cDNA library. These toxins showed significant similarity at the amino acid level with spider toxins from Lasiodora parahybana, Eurypelma californicum, Brachypelma smithii, Selenocosmia huwena.
Collapse
Affiliation(s)
- A L G Vieira
- Laboratório de Biologia Celular e Molecular, Núcleo de Pesquisa em Ciências Biológicas, Universidade Federal de Ouro Preto, Campus do Morro do Cruzeiro, Ouro Preto, MG 35.400-00, Brazil
| | | | | | | | | | | |
Collapse
|
21
|
de Castro CS, Silvestre FG, Araújo SC, Gabriel DMY, Mangili OC, Cruz I, Chávez-Olórtegui C, Kalapothakis E. Identification and molecular cloning of insecticidal toxins from the venom of the brown spider Loxosceles intermedia. Toxicon 2004; 44:273-80. [PMID: 15302533 DOI: 10.1016/j.toxicon.2004.05.028] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2004] [Revised: 05/24/2004] [Accepted: 05/25/2004] [Indexed: 11/23/2022]
Abstract
The venom of Loxosceles intermedia was investigated for the presence of insecticidal toxins active against Spodoptera frugiperda (Lepdoptera: Noctuidade), an insect that has caused great reductions in corn production in Brazil. A combination of gel filtration (Sephadex G-100) and ion-exchange chromatography (Carboxymethyl Cellulose, CM 52) resulted in four major fractions that were submitted to biological assay. Fraction 4 was further purified by a reverse phase HPLC (C18 Column) resulting in peptides active against Spodoptera frugiperda. Three new potential insecticidal toxins named LiTx x 1, LiTx x 2 and LiTx x 3 were identified. The partial amino terminal sequences of these peptides were obtained and used to clone the corresponding cDNAs with the help of degenerate oligonucleotides. The amino acid sequence deduced from the cDNA of LiTx x 1, LiTx x 2 and LiTx x 3 revealed mature proteins of approximately 7.4, 7.9 and 5.6 kDa.
Collapse
Affiliation(s)
- Cibele Soares de Castro
- Departamento de Farmacologia, ICB, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte Cep: 31270901, MG, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
22
|
de O Beleboni R, Pizzo AB, Fontana ACK, de O G Carolino R, Coutinho-Netto J, Dos Santos WF. Spider and wasp neurotoxins: pharmacological and biochemical aspects. Eur J Pharmacol 2004; 493:1-17. [PMID: 15189759 DOI: 10.1016/j.ejphar.2004.03.049] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Accepted: 03/25/2004] [Indexed: 10/26/2022]
Abstract
Venoms from several arthropods are recognized as useful sources of bioactive substances, such as peptides, acylpolyamines, and alkaloids, which show a wide range of pharmacological effects on synaptic transmission. In this work, we summarize and compile several biochemical and pharmacological aspects related to spider and wasp neurotoxins. Their inhibitory and stimulatory actions on ion channels, receptors, and transporters involved in mammalian and insect neurotransmission are considered.
Collapse
Affiliation(s)
- Renê de O Beleboni
- Department of Biochemistry and Immunology, School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
Arthropods are the most diverse animal group on the planet. Their ability to inhabit a vast array of ecological niches has inevitably brought them into conflict with humans. Although only a small minority are classified as pest species, they nevertheless destroy about a quarter of the world's annual crop production and transmit an impressive array of pathogens of human and veterinary public health importance. Arthropod pests have been controlled almost exclusively with chemical insecticides since the introduction of DDT in the 1940s. However, the evolution of resistance to many insecticides, coupled with increased awareness of the potential environmental and human and animal health impacts of these chemicals, has stimulated the search for new insecticidal compounds, novel molecular targets, and alternative control methods. Spider venoms are complex chemical cocktails that have evolved to kill or paralyze arthropod prey, and they represent a largely untapped reservoir of insecticidal compounds. This review focuses on several families of invertebrate-specific peptide neurotoxins that were isolated from the venom of Australian funnel-web spiders. These peptides are promising insecticide leads because of their selectivity for invertebrates and activity on previously unvalidated targets. These toxins should facilitate the development of novel target-based screens for new insecticide leads, while their mapped pharmacophores will provide templates for rational design of mimetics that act at these target sites. Furthermore, genes encoding these toxins can be used to improve the efficacy of insect-specific viruses.
Collapse
Affiliation(s)
- Hugo W Tedford
- Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06032-3305, USA
| | | | | | | |
Collapse
|
24
|
Kuhn-Nentwig L, Schaller J, Nentwig W. Biochemistry, toxicology and ecology of the venom of the spider Cupiennius salei (Ctenidae). Toxicon 2004; 43:543-53. [PMID: 15066412 DOI: 10.1016/j.toxicon.2004.02.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The venom of Cupiennius salei consists of many low molecular compounds, nine neurotoxic acting peptides (CSTX), at least eight neurotoxic and cytolytic acting peptides (cupiennins), a highly active hyaluronidase, and several hitherto unidentified proteins. The structure of several peptides is given. A synergistic action between three main groups is proposed: injected into the prey tissue, the enzyme hyaluronidase acts as a spreading factor, thus, facilitating a better access of venom neurotoxins to their targets, cupiennins disturb cell membranes and influence cell excitability, through this augmenting the mere neurotoxic effect of CSTX-1 synergistically. The venom glands of an apocrine secretion type provide an average of 12 microl per milking (adult female). Venom sensitivity of arthropods differs between 0.001 and >20nl venom/mg insect. Regeneration time of an empty venom gland is approx. 2 weeks. Consequently, spiders may encounter situations in which they have to decide whether their limited venom storage is sufficient to kill a given prey item. Experiments are presented which show that C. salei knows the actual venom content of its venom glands. It injects no more venom than necessary. This coincides with an experimentally determined LD(50) value in harmless prey items, but C. salei injects more venom in aggressive or otherwise dangerous prey items (quantification of injected venom amounts by monoclonal antibodies). These results indicate that C. salei uses its venom as economically as possible and this supports our venom optimisation hypothesis.
Collapse
Affiliation(s)
- Lucia Kuhn-Nentwig
- Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
| | | | | |
Collapse
|
25
|
Abstract
Agatoxins from Agelenopsis aperta venom target three classes of ion channels, including transmitter-activated cation channels, voltage-activated sodium channels, and voltage-activated calcium channels. The alpha-agatoxins are non-competitive, use-dependent antagonists of glutamate receptor channels, and produce rapid but reversible paralysis in insect prey. Their actions are facilitated by the micro-agatoxins, which shift voltage-dependent activation of neuronal sodium channels to more negative potentials, causing spontaneous transmitter release and repetitive action potentials. The omega-agatoxins target neuronal calcium channels, modifying their properties in distinct ways, either through gating modification (omega-Aga-IVA) or by reduction of unitary current (omega-Aga-IIIA). The alpha-agatoxins and omega-agatoxins modify both insect and vertebrate ion channels, while the micro-agatoxins are selective for insect channels. Agatoxins have been used as selective pharmacological probes for characterization of ion channels in the brain and heart, and have been evaluated as candidate biopesticides.
Collapse
Affiliation(s)
- Michael E Adams
- Department of Entomology, 5429 Boyce Hall, University of California, Riverside CA 92521, USA.
| |
Collapse
|
26
|
Fitches E, Edwards MG, Mee C, Grishin E, Gatehouse AMR, Edwards JP, Gatehouse JA. Fusion proteins containing insect-specific toxins as pest control agents: snowdrop lectin delivers fused insecticidal spider venom toxin to insect haemolymph following oral ingestion. JOURNAL OF INSECT PHYSIOLOGY 2004; 50:61-71. [PMID: 15037094 DOI: 10.1016/j.jinsphys.2003.09.010] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2003] [Revised: 09/25/2003] [Accepted: 09/26/2003] [Indexed: 05/21/2023]
Abstract
The mannose-specific snowdrop lectin (Galanthus nivalis agglutinin: GNA), when fed to insects, binds to the gut epithelium and passes into the haemolymph. The ability of GNA to act as a carrier protein to deliver an insecticidal spider venom neurotoxin (Segestria florentina toxin 1: SFI1) to the haemolymph of lepidopteran larvae was investigated. Constructs encoding SFI1 and an SFI1/GNA fusion protein were expressed in Pichia pastoris. The insecticidal activity of purified recombinant proteins on injection was found to be comparable to published values for SfI1 purified from spider venom [Toxicon 40 (2002) 125]. Whereas neither GNA nor SFI1 alone showed acute toxicity when fed to larvae of tomato moth (Lacanobia oleracea), feeding SFI1/GNA fusion at 2.5% of dietary proteins was insecticidal to first stadium larvae, causing 100% mortality after 6 days. The protein also showed a significant, dose dependent, toxicity towards fourth and fifth stadium larvae, with growth reduced by up to approximately 90% over a 4-day assay period compared to controls. Delivery of intact SFI1/GNA to the haemolymph in these insects was shown by western blotting; haemolymph samples from fusion-fed larvae contained a GNA-immunoreactive protein of the same molecular weight as the SFI1/GNA fusion. SFI1/GNA and similar fusion proteins offer a novel and effective approach for delivering haemolymph active toxins by oral administration, which could be used in crop protection by expression in transgenic plants.
Collapse
Affiliation(s)
- Elaine Fitches
- Central Science Laboratory, Department for Environment, Food and Rural Affairs, Sand Hutton, York YO41 1LZ, UK
| | | | | | | | | | | | | |
Collapse
|
27
|
Bondebjerg J, Grunnet M, Jespersen T, Meldal M. Solid-phase synthesis and biological activity of a thioether analogue of conotoxin G1. Chembiochem 2003; 4:186-94. [PMID: 12616632 DOI: 10.1002/cbic.200390030] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A bicyclic thioether analogue of alpha-conotoxin G1, a neurotoxin found in the venom of cone snails, was synthesized on solid phase. Two successive intramolecular on-bead cyclizations between a cysteine residue and a chloroacetylated reduced peptide bond are the key steps in the synthesis. The first reduced peptide bond was introduced by a reductive alkylation with a 9-fluorenylmethoxycarbonyl protected amino aldehyde, and the second by coupling of a dipeptide building block containing an allyloxycarbonyl protected reduced peptide bond. The desired bicyclic product was obtained as a mixture of two isomers, which were evaluated for their ability to inhibit the muscular nicotinic acetylcholine receptor expressed in Xenopus oocytes. The two isomers were found to have IC(50) values (inhibitory activities) of 144 microM and 48 microM, compared to 0.18 microM for native conotoxin G1.
Collapse
Affiliation(s)
- Jon Bondebjerg
- SPOCC Centre, Carlsberg Laboratory, Department of Chemistry, Gamle Carlsbergvej 10, 2500 Valby, Denmark
| | | | | | | |
Collapse
|
28
|
Abstract
Spider venoms represent an incredible source of biologically active substances which selectively target a variety of vital physiological functions in both insects and mammals. Many toxins isolated from spider venoms have been invaluable in helping to determine the role and diversity of neuronal ion channels and the process of exocytosis. In addition, there is enormous potential for the use of insect specific toxins from animal sources in agriculture. For these reasons, the past 15-20 years has seen a dramatic increase in studies on the venoms of many animals, particularly scorpions and spiders. This review covers the pharmacological and biochemical activities of spider venoms and the nature of the active components. In particular, it focuses on the wide variety of ion channel toxins, novel non-neurotoxic peptide toxins, enzymes and low molecular weight compounds that have been isolated. It also discusses the intraspecific sex differences in given species of spiders.
Collapse
Affiliation(s)
- Lachlan D Rash
- Monash Venom Group, Department of Pharmacology, PO Box 13E, Monash University, Victoria 3800, Australia
| | | |
Collapse
|
29
|
Lipkin A, Kozlov S, Nosyreva E, Blake A, Windass JD, Grishin E. Novel insecticidal toxins from the venom of the spider Segestria florentina. Toxicon 2002; 40:125-30. [PMID: 11689233 DOI: 10.1016/s0041-0101(01)00181-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three insecticidal polypeptide toxins (F5.5, F5.6, F5.7) with molecular masses 4973, 4993 and 5159Da were isolated from the venom of the central Asian spider Segestria florentina. These toxins caused the complete flaccid paralysis of Heliothis virescens (Lepidoptera: Noctuidae) larvae (LD(50) 4-10 microg/g), whereas they were inactive upon intravenous injections into mice. On the basis of N-terminal amino acid sequences a family of eight genes encoding highly homologues polypeptides (SFI1-SFI8) was revealed, some of which encode polypeptides actually demonstrated to be present in S. florentina venom. All deduced polypeptides consist of 46 amino acids residues. Comparison of primary structures of SFI1-SFI8 with other spider toxins suggests that this family might share structural and functional relationships with other small spider neurotoxins, several of which are known to be highly selective agonists/antagonists of different voltage-dependent Ca(2+) channels.
Collapse
Affiliation(s)
- A Lipkin
- Laboratory of Neuroreceptors and Neuroregulators, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | | | | | | | | | | |
Collapse
|
30
|
de Figueiredo SG, de Lima ME, Nascimento Cordeiro M, Diniz CR, Patten D, Halliwell RF, Gilroy J, Richardson M. Purification and amino acid sequence of a highly insecticidal toxin from the venom of the brazilian spider Phoneutria nigriventer which inhibits NMDA-evoked currents in rat hippocampal neurones. Toxicon 2001; 39:309-17. [PMID: 10978749 DOI: 10.1016/s0041-0101(00)00129-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A new insecticidal toxin Tx4(5-5) was isolated from the fraction PhTx4 of the venom of the spider Phoneutria nigriventer by reverse phase high performance liquid chromatography (HPLC) and anion exchange HPLC. The complete amino acid sequence determined by automated Edman degradation showed that Tx4(5-5) is a single chain polypeptide composed of 47 amino acid residues, including 10 cysteines, with a calculated molecular mass of 5175 Da. Tx4(5-5) shows 64% of sequence identity with Tx4(6-1), another insecticidal toxin from the same venom. Tx4(5-5) was highly toxic to house fly (Musca domestica), cockroach (Periplaneta americana) and cricket (Acheta domesticus ), producing neurotoxic effects (knock-down, trembling with uncoordinated movements) at doses as low as 50 ng/g (house fly), 250 ng/g (cockroach) and 150 ng/g (cricket). In contrast, intracerebroventricular injections (30 microg) into mice induced no behavioural effects. Preliminary electrophysiological studies carried out on whole-cell voltage-clamped rat hippocampal neurones indicated that Tx4(5-5) (at 1 microM) reversibly inhibited the N-methyl-D-aspartate-subtype of ionotropic glutamate receptor, while having little or no effect on kainate-, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid- or gamma-aminobutyric acid-activated currents.
Collapse
Affiliation(s)
- S G de Figueiredo
- Departmento de Ciencias Fisiologicas, Universidade Federal do Espirito Santo, Vitoria, ES, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Corzo G, Escoubas P, Stankiewicz M, Pelhate M, Kristensen CP, Nakajima T. Isolation, synthesis and pharmacological characterization of delta-palutoxins IT, novel insecticidal toxins from the spider Paracoelotes luctuosus (Amaurobiidae). EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:5783-95. [PMID: 10971590 DOI: 10.1046/j.1432-1327.2000.01653.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Four novel insecticidal toxins were isolated from the venom of the spider Paracoelotes luctuosus (Araneae: Amaurobiidae) and named delta-palutoxins IT1 to IT4. The four toxins are homologous 36-37 amino acid peptides reticulated by four disulfide bridges and three have amidated C-terminal residues. The delta-palutoxins are highly homologous with the previously described mu-agatoxins and curtatoxins (77-97%). The four peptides demonstrated significant toxicity against larvae of the crop pest Spodoptera litura (Lepidoptera: Noctuidae) in a microinjection bioassay, with LD50 values in the 9-50 microg per g of insect range. This level of toxicity is equivalent to that of several of the most active scorpion toxins used in the development of recombinant baculoviruses, and the delta-palutoxins appear to be insect specific. Electrophysiological experiments demonstrated that delta-palutoxin IT1, the most active toxin acts by affecting insect sodium channel inactivation, resulting in the appearance of a late-maintained sodium current, in a similar fashion to insecticidal scorpion alpha and alpha-like toxins and is thus likely to bind to channel receptor site 3. However, delta-palutoxin IT1 was distinguished by its lack of effect on peak sodium conductance, on the early phase of sodium current inactivation and the absence of a shift in the activation voltage of the sodium channels. delta-Palutoxins are thus proposed as new insecticidal toxins related to the alpha and alpha-like scorpion toxins. They will be useful both in the development of recombinant baculoviruses in agrochemical applications and also as molecular probes for the investigation of molecular mechanisms of insect selectivity and structure and function of sodium channels.
Collapse
Affiliation(s)
- G Corzo
- Suntory Institute for Bioorganic Research, Osaka, Japan; Laboratoire de Neurophysiologie, Université d'Angers, France.
| | | | | | | | | | | |
Collapse
|
32
|
Marvin L, De E, Cosette P, Gagnon J, Molle G, Lange C. Isolation, amino acid sequence and functional assays of SGTx1. The first toxin purified from the venom of the spider scodra griseipes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 265:572-9. [PMID: 10504388 DOI: 10.1046/j.1432-1327.1999.00726.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A new toxin (SGTx1) was purified from the venom of the spider Scodra griseipes by a combination of gel filtration and reverse-phase chromatography. The complete amino acid sequence of SGTx1, TCRYLFGGCKTTADCCKHLACRSDGKYCAWDGTF, was established by direct automated Edman degradation, and is in perfect agreement with the molecular mass of 3775 Da found by mass spectrometry. The primary structure of SGTx1 exhibited sequence identity with other spider toxins such as hanatoxin (76%), TxP5 toxin (32%) and huwentoxin (26%). The six cysteines in the sequence suggested three disulfide bridges, the presence of which was demonstrated by mass spectrometry after dithiothreitol reduction. Analysis of secondary structure using circular dichroism spectrometry yielded more than 50% beta-sheet and about 15-20% beta-turn. The extent of the beta-content and the presence of disulfide bridges suggest a structure of interconnected beta-strands. In addition, a study of membrane/toxin interactions was carried out by reconstitution in planar lipid bilayers and by antibacterial assays. SGTx1 displays moderate pore-forming ability (conductance of about 100 pS in 1 M NaCl), but antibacterial activity was not observed against Gram-positive or Gram-negative strains. As a preliminary assay, the activity of SGTx1 was investigating using electrophysiological measurements. At 0.15 microM, SGTx1 reversibly inhibits more than 40% of outward potassium currents in rat cerebellum granular cells. This result is reminiscent with the effect described for hanatoxin extracted from the venom of Grammostola spatulata.
Collapse
Affiliation(s)
- L Marvin
- Spectrométrie de Masse Bio-oRGANIQUE cnrs-upresa 6014, Mont Saint Aignan, France
| | | | | | | | | | | |
Collapse
|
33
|
Osaki T, Omotezako M, Nagayama R, Hirata M, Iwanaga S, Kasahara J, Hattori J, Ito I, Sugiyama H, Kawabata S. Horseshoe crab hemocyte-derived antimicrobial polypeptides, tachystatins, with sequence similarity to spider neurotoxins. J Biol Chem 1999; 274:26172-8. [PMID: 10473569 DOI: 10.1074/jbc.274.37.26172] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Antimicrobial peptides, named tachystatins A, B, and C, were identified from hemocytes of the horseshoe crab Tachypleus tridentatus. Tachystatins exhibited a broad spectrum of antimicrobial activity against Gram-negative and Gram-positive bacteria and fungi. Of these tachystatins, tachystatin C was most effective. Tachystatin A is homologous to tachystatin B, but tachystatin C has no significant sequence similarity to tachystatins A and B. Tachystatins A and B showed sequence similarity to omega-agatoxin-IVA of funnel web spider venom, a potent blocker of voltage-dependent calcium channels. However, they exhibited no blocking activity of the P-type calcium channel in rat Purkinje cells. Tachystatin C also showed sequence similarity to several insecticidal neurotoxins of spider venoms. Tachystatins A, B, and C bound significantly to chitin. A causal relationship was observed between chitin binding activity and antifungal activity. Tachystatins caused morphological changes against a budding yeast, and tachystatin C had a strong cell lysis activity. The septum between mother cell and bud, a chitin-rich region, was stained by fluorescence-labeled tachystatin C, suggesting that the primary recognizing substance on the cell wall is chitin. As horseshoe crab is a close relative of the spider, tachystatins and spider neurotoxins may have evolved from a common ancestral peptide, with adaptive functions.
Collapse
Affiliation(s)
- T Osaki
- Department of Molecular Biology, Graduate School of Medical Science, Fukuoka 812-8582, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
Spider venoms contain a variety of toxic components. The polypeptide toxins are divided into low and high molecular mass types. Small polypeptide toxins interacting with cation channels display spatial structure homology. They can affect the functioning of calcium, sodium, or potassium channels. A family of high molecular mass toxic proteins was found in the venom of the spider genus Latrodectus. These neurotoxins, latrotoxins, cause a massive transmitter release from a diversity of nerve endings. The latrotoxins are proteins of about 1000 amino acid residues and share a high level of structure identity. The structural and functional properties of spider polypeptide toxins are reviewed in this paper.
Collapse
Affiliation(s)
- E Grishin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| |
Collapse
|
35
|
|
36
|
Temple MD, Hinds MG, Sheumack DD, Howden ME, Norton RS. 1H NMR study of robustoxin, the lethal neurotoxin from the funnel web spider Atrax robustus. Toxicon 1999; 37:485-506. [PMID: 10080353 DOI: 10.1016/s0041-0101(98)00186-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Robustoxin, the lethal neurotoxin from the Sydney funnel web spider Atrax robustus, is a polypeptide of 42 residues cross-linked by four disulfide bonds. This paper describes the sequence-specific assignment of resonances in the 1H nuclear magnetic resonance spectrum of robustoxin in aqueous solution. Several broad backbone amide resonances were encountered in spectra recorded at 27 degrees C, making the assignments at that temperature incomplete. In spectra recorded at lower temperatures these amide resonances became sharper, but others that were sharp at 27 degrees C became broad, indicative of conformational averaging on the millisecond timescale for certain regions of the structure. Nevertheless, it was possible to establish that robustoxin contains a small, triple-stranded, antiparallel beta-sheet and several reverse turns, but no alpha-helix. These observations indicate that this toxin may adopt the inhibitor cystine knot structure found in polypeptides from a diverse range of species, including a number of spiders. Analysis of the pH dependence of the spectrum yielded pKa values for Tyr22 and Tyr25, one of the three carboxyl groups, and the Lys residues.
Collapse
Affiliation(s)
- M D Temple
- School of Biochemistry and Molecular Genetics, University of New South Wales, Sydney, Australia
| | | | | | | | | |
Collapse
|
37
|
Ali SA, Stoeva S, Schütz J, Kayed R, Abassi A, Zaidi ZH, Voelter W. Purification and primary structure of low molecular mass peptides from scorpion (Buthus sindicus) venom. Comp Biochem Physiol A Mol Integr Physiol 1998; 121:323-32. [PMID: 10048185 DOI: 10.1016/s1095-6433(98)10140-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The primary structures of four low molecular mass peptides (Bs 6, 8, 10 and 14) from scorpion Buthus sindicus were elucidated via combination of Edman degradation and matrix-assisted laser desorption ionization mass spectrometry. Bs 8 and 14 are cysteine-rich, thermostable peptides composed of 35-36 residues with molecular weights of 3.7 and 3.4 kDa, respectively. These peptides show close sequence homologies (55-78%) with other scorpion chlorotoxin-like short-chain neurotoxins (SCNs) containing four intramolecular disulfide bridges. Despite the sequence variation between these two peptides (37% heterogeneity) their general structural organization is very similar as shown by their clearly related circular dichroism spectra. Furthermore, Bs6 is a minor component, composed of 38 residues (4.1 kDa) containing six half-cystine residues and having close sequence identities (40-80%) with charybdotoxin-like SCNs containing three disulfide bridges. The non-cysteinic, bacic and thermolabile Bs10 is composed of 34 amino acid residues (3.7 kDa), and belongs to a new class of peptides, with no sequence resemblance to any other so far reported sequence isolated from scorpions. Surprisingly, Bs10 shows some limited sequence analogy with oocyte zinc finger proteins. Results of these studies are discussed with respect to their structural similarities within the scorpion LCNs, SCNs and other biologically active peptides.
Collapse
Affiliation(s)
- S A Ali
- International Centre for Chemical Sciences, University of Karachi, Pakistan.
| | | | | | | | | | | | | |
Collapse
|
38
|
Kalapothakis E, Penaforte CL, Leão RM, Cruz JS, Prado VF, Cordeiro MN, Diniz CR, Romano-Silva MA, Prado MA, Gomez MV, Beirão PS. Cloning, cDNA sequence analysis and patch clamp studies of a toxin from the venom of the armed spider (Phoneutria nigriventer). Toxicon 1998; 36:1971-80. [PMID: 9839681 DOI: 10.1016/s0041-0101(98)00127-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The cDNAs (Tx3-2 and Pn3A) encoding precursor of toxin Tx3-2 and an isoform called Pn3A have been isolated from a library constructed from stimulated venom glands of the spider Phoneutria nigriventer. The cDNA of Tx3-2 reveals the presence of a signal peptide of 21 amino acids and of an intervening propeptide (with 16 amino acids) preceding the toxin sequence, which was followed by additional amino acid residues at the C-terminus (C-terminal peptide), implying post-translational modifications of the synthesised peptide. The deduced amino acid sequence for the mature toxin confirms the previous sequence published. In addition, by using the whole-cell patch clamp technique, we have determined that purified Tx3-2 decreases L-type currents present in GH3 cells. Finally, the presence of the cDNA Pn3A, with high sequence identity with Tx3-2, reveals the existence of a putative new toxin showing, at the cDNA level, 85.4% identity in its whole segment.
Collapse
Affiliation(s)
- E Kalapothakis
- Departamento de Farmacologia, Instituto de Ciências Biològicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Sutton KG, Siok C, Stea A, Zamponi GW, Heck SD, Volkmann RA, Ahlijanian MK, Snutch TP. Inhibition of neuronal calcium channels by a novel peptide spider toxin, DW13.3. Mol Pharmacol 1998; 54:407-18. [PMID: 9687583 DOI: 10.1124/mol.54.2.407] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Peptide toxins have proved to be useful agents, both in discriminating between different components of native calcium channel currents and in the molecular isolation and designation of their cloned channel counterparts. Here, we describe the isolation and characterization of the biochemical and physiological properties of a novel 74-amino acid peptide toxin (DW13.3) extracted from the venom of the spider Filistata hibernalis. The subtype specificity of DW13.3 was investigated using calcium channel currents recorded from two separate expression systems and several different cultured mammalian cell preparations. Overall, DW13.3 potently blocked all native calcium channel currents studied, with the exception of T-type currents recorded from GH3 cells. Examination of transiently expressed calcium channels in oocytes showed that DW13.3 had the highest affinity for alpha1A, followed by alpha1B > alpha1C > alpha1E. The affinity of DW13.3 for alpha1B N-type currents varied by 10-fold between expressed channels and native currents. Although block occurred in a similar 1:1 manner for all subtypes, DW13.3 produced a partial block of both alpha1A currents and P-type currents in cerebellar Purkinje cells. Selective occlusion of the P/Q-type channel ligand omega-conotoxin MVIIC (but not omega-agatoxin IVA) from its binding site in Purkinje neurons suggests that DW13.3 binds to a site close to the pore of the channel. The inhibition of different subtypes of calcium channels by DW13.3 reflects a common "macro" binding site present on all calcium channels except T-type.
Collapse
Affiliation(s)
- K G Sutton
- Biotechnology Laboratory, University of British Columbia, Vancouver, B.C., Canada V6T 1Z3
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Johnson JH, Bloomquist JR, Krapcho KJ, Kral RM, Trovato R, Eppler KG, Morgan TK, DelMar EG. Novel insecticidal peptides from Tegenaria agrestis spider venom may have a direct effect on the insect central nervous system. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 1998; 38:19-31. [PMID: 9589602 DOI: 10.1002/(sici)1520-6327(1998)38:1<19::aid-arch3>3.0.co;2-q] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Fractionation of venom from an agelenid spider, Tegenaria agrestis, resulted in the isolation of a family of three peptides with potent insecticidal activity. These peptide toxins, TaITX-1, -2, and -3, whose sequences were revealed from cloned cDNAs, each consist of 50 amino acid residues, six of which are cysteines. They appear to be amidated at their C-termini and exhibit greater than 90% sequence identity. Unlike other reported spider toxins, the TaI toxins are processed from precursors containing no propeptide sequences. In lepidopteran larvae and corn rootworm beetles, the insecticidal Tegenaria toxins caused an unusual excitatory symptomatology with 50% paralytic doses ranging from 0.23 to 2.6 nmol/g. In a series of electrophysiological experiments performed in house fly larvae, these toxins caused an elevated rate of firing from central nervous system neurons. No significant effects were found when any peripheral sensory or motor systems were examined. Thus, it appears that the TaI toxins may act in a fashion not previously reported for insecticidal peptide toxins; they may act directly on the insect central nervous system.
Collapse
Affiliation(s)
- J H Johnson
- NPS Pharmaceuticals, Salt Lake City, Utah 84108, USA.
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Nicholson GM, Little MJ, Tyler M, Narahashi T. Selective alteration of sodium channel gating by Australian funnel-web spider toxins. Toxicon 1996; 34:1443-53. [PMID: 9028001 DOI: 10.1016/s0041-0101(96)00089-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The actions of potent mammalian neurotoxins isolated from the venom of two Australian funnel-web spiders were investigated using both electrophysiological and neurochemical techniques. Whole-cell patch clamp recording of sodium currents in rat dorsal root ganglion neurons revealed that versutoxin (VTX), isolated from the venom of Hadronyche versuta, produced a concentration-dependent slowing or removal of tetrodotoxin-sensitive (TTX-S) sodium current inactivation and a reduction in peak TTX-S sodium current. In contrast, VTX had no effect on tetrodotoxin-resistant (TTX-R) sodium currents or potassium currents. VTX also shifted the voltage dependence of sodium channel activation in the hyperpolarizing direction and increased the rate of recovery from inactivation. Ion flux studies performed in rat brain synaptosomes also revealed that robustoxin (RTX), from the venom of Atrax robustus, and VTX both produced a partial activation of 22Na+ flux and an inhibition of batrachotoxin-activated 22Na+ flux. This inhibition of flux through batrachotoxin-activated channels was not due to an interaction with neurotoxin receptor site 1 since [3H]saxitoxin binding was unaffected. In addition, the partial activation of 22Na+ flux was not enhanced in the presence of alpha-scorpion toxin and further experiments suggest that VTX also enhances [3H]batrachotoxin binding. These selective actions of funnel-web spider toxins on sodium channel function are comparable to those of alpha-scorpion and sea anemone toxins which bind to neurotoxin receptor site 3 on the channel to slow channel inactivation profoundly. Also, these modifications of sodium channel gating and kinetics are consistent with actions of the spider toxins to produce repetitive firing of action potentials.
Collapse
Affiliation(s)
- G M Nicholson
- Department of Health Sciences, University of Technology, Sydney, NSW, Australia
| | | | | | | |
Collapse
|
42
|
Boevé JL, Kuhn-Nentwig L, Keller S, Nentwig W. Quantity and quality of venom released by a spider (Cupiennius salei, Ctenidae). Toxicon 1995; 33:1347-57. [PMID: 8599185 DOI: 10.1016/0041-0101(95)00066-u] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The amount of venom injected by the spider Cupiennius salei depended on the efficiency of the mechanical defence of the prey species. Spiders were milked for the first venom (i.e. the first microlitre of venom emitted) versus remaining venom, and for venom regenerated from emptied glands. HPLC gel filtration and IEF electrophoresis showed that the protein content of the first venom was only half as compared to that of the remaining venom, and that this was due to a dilution of all proteins. Venom regeneration came in two speeds. The amount of venom was regenerated more rapidly than the protein concentration. Newly regenerated venom as compared to older venom was characterized by a lower concentration of all proteins and by a higher total concentration of free amino acids, whereas histamine and taurine did not follow this trend. K+ concentration and pH remained similar during venom regeneration. Crickets injected with the venoms showed less acute symptoms when the protein concentration was lower, namely with the first venom and with newly regenerated venom. Consequently, a spider which modulates the quantity of venom injected into a prey also directly changes the venom quality. The ecological consequences of this are discussed. This paper also discusses which region of a gland (ampulla, extracellular and intracellular parts of the glandular sac) is involved in the changes of the venom quality.
Collapse
Affiliation(s)
- J L Boevé
- Zoologisches Institut, Universität Bern, Switzerland
| | | | | | | |
Collapse
|
43
|
Krapcho KJ, Kral RM, Vanwagenen BC, Eppler KG, Morgan TK. Characterization and cloning of insecticidal peptides from the primitive weaving spider Diguetia canities. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 1995; 25:991-1000. [PMID: 8541888 DOI: 10.1016/0965-1748(95)00029-u] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Three potent insecticidal peptide toxins were purified from the venom of the primitive weaving spider, Diguetia canities. The toxins share significant homology (> 40%) in their amino acid sequences and are of related size (masses of 6371-7080 Da). In lepidopteran larvae, the toxins cause a progressive spastic paralysis, with 50% paralytic doses (PD50S) ranging from 0.38 to 3.18 nmol/g, suggesting them to be among the most potent insecticidal compounds yet described from arthropod venoms. The most potent of these toxins, DTX9.2, was cloned using a reverse transcription-polymerase chain reaction (RT-PCR). The cDNA encodes a 94 amino acid precursor which is processed to the active 56 amino acid peptide by removal of a signal and propeptide sequence. The gene encoding DTX9.2 was isolated and characterized. The transcriptional unit spans 5.5 kilobases and is segregated into five exons. DNA sequences upstream from the first exon contain a TATA box and two palindromic sequences (one with homology to a CAAT consensus) which together may constitute a functional promoter. The highly segmented gene structure observed for this small peptide suggests that a mechanism such as exon shuffling may have played a role in the evolution of this toxin family.
Collapse
Affiliation(s)
- K J Krapcho
- Department of Molecular Biology, NPS Pharmaceuticals, Inc., Salt Lake City, UT 84108, USA
| | | | | | | | | |
Collapse
|
44
|
Newcomb R, Palma A, Fox J, Gaur S, Lau K, Chung D, Cong R, Bell JR, Horne B, Nadasdi L. SNX-325, a novel calcium antagonist from the spider Segestria florentina. Biochemistry 1995; 34:8341-7. [PMID: 7541240 DOI: 10.1021/bi00026a015] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A novel selective calcium channel antagonist peptide, SNX-325, has been isolated from the venom of the spider Segestria florentina. The peptide was isolated using as bioassays the displacement of radioiodinated omega-conopeptide SNX-230 (MVIIC) from rat brain synaptosomal membranes, as well as the inhibition of the barium current through cloned expressed calcium channels in oocytes. The primary sequence of SNX-325 is GSCIESGKSCTHSRSMKNGLCCPKSRCNCRQIQHRHDYLGKRKYSCRCS, which is a novel amino acid sequence. Solid-phase synthesis resulted in a peptide that is chromatographically identical with the native peptide and which has the same configuration of cysteine residues as the spider venom peptide omega-Aga-IVa [Mintz, I. M., et al., (1992) Nature 355, 827-829]. At micromolar concentrations, SNX-325 is an inhibitor of most calcium, but not sodium or potassium, currents. At nanomolar concentrations, SNX-325 is a selective blocker of the cloned expressed class B (N-type), but not class C (cardiac L), A, or E, calcium channels. SNX-325 is approximately equipotent with the N-channel selective omega-conopeptides (GVIA and MVIIA as well as closely related synthetic derivatives) in blocking the potassium induced release of tritiated norepinephrine from hippocampal slices (IC50s, 0.1-0.5 nM) and in blocking the barium current through cloned expressed N-channels in oocytes (IC50s 3-30 nM). By contrast, SNX-325 is 4-5 orders of magnitude less potent than is SNX-111 (synthetic MVIIA) at displacing radioiodinated SNX-111 from rat brain synaptosomal membranes. SNX-325 will be a useful comparative tool in further defining the function and pharmacology of the N- and possibly other types of high-voltage activated calcium channels.
Collapse
Affiliation(s)
- R Newcomb
- Neurex Corporation, Menlo Park, California 94025-1012, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Bento AC, Rego E, Pedroso-Mariani SR, Mancuso LC, Giglio JR, Novello JC, Marangoni S, Caracelli I, Oliveira B, Antunes E. Isolation of a polypeptide from Phoneutria nigriventer spider venom responsible for the increased vascular permeability in rabbit skin. Toxicon 1995; 33:171-8. [PMID: 7597720 DOI: 10.1016/0041-0101(94)00148-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fractionation of Phoneutria nigriventer venom by Sephadex G-10 followed by ion-exchange chromatography yields a fraction (fraction XIII) which increases microvascular permeability in rabbit skin in vivo by activating the tissue kallikrein-kinin system. One polypeptide (PNV3) with the ability to increase microvascular permeability in the rabbit skin in vivo was isolated from fraction XIII and biochemically characterized. PNV3 has 132 amino acid residues with a calculated mol. wt of 14,475. This polypeptide showed the following N-terminal sequence: AVFAIQDQPC. Amino acid analysis indicated the presence of six disulfide bridges and a high content of Glx (20%). Pairwise comparison of PNV3 amino acid sequence with 27 other spider venom polypeptides and proteins indicated that PNV3 presents high similarity (60-70%) with other toxins (Tx2.1, Tx2.5 and Tx2.6) isolated from P. nigriventer venom.
Collapse
Affiliation(s)
- A C Bento
- Department of Pharmacology, State University of Campinas (UNICAMP), SP, Brazil
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Abstract
Venoms of the predatory cone snails Conus textile, Conus striatus, and Conus magus were subjected to comprehensive analysis of peptide content. With the fish-eating cone snails C. magus and C. striatus, the most abundant venom peptides were of > 30-50 residues, whereas the predominant peptides in the venom of the mollusc-eating snail, C. textile, were of 20-35 residues. Amino acid sequencing revealed an identical but unusual amino acid in a conserved position in four novel omega-type peptides from the C. textile venom. Two conserved amino acid sequences were obtained from the venoms of both C. magus and C. striatus. The amino acid compositions of the isolated C. textile peptides and the expected processing products of the propeptides (42) were compared. Despite the recovery in abundance of the carboxyl-terminal omega-type peptides, none of the isolated peptides had compositions expected from the propeptide amino-terminal fragments. We conclude that there are likely mechanisms for excluding the amino-terminal propeptide fragments from this venom, resulting in a venom with greater potency. Amounts of the different omega-type peptides in the venom vary widely, suggesting a distinct mechanism that results in the selective synthesis of different bioactive carboxyl-terminal propeptide fragments at elevated levels.
Collapse
Affiliation(s)
- R Newcomb
- Neurex Corp., Menlo Park, CA 94025, USA
| | | | | | | |
Collapse
|
47
|
Figueiredo SG, Garcia ME, Valentim AC, Cordeiro MN, Diniz CR, Richardson M. Purification and amino acid sequence of the insecticidal neurotoxin Tx4(6-1) from the venom of the 'armed' spider Phoneutria nigriventer (Keys). Toxicon 1995; 33:83-93. [PMID: 7778132 DOI: 10.1016/0041-0101(94)00130-z] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An insecticidal peptide referred to as Tx4(6-1) was purified from the venom of the spider Phoneutria nigriventer by a combination of gel filtration, reverse-phase fast liquid chromatography on Pep-RPC, reverse-phase high performance liquid chromatography (HPLC) on Vydac C18 and ion-exchange HPLC on cationic columns. Tx4(6-1) is highly toxic to house flies. At levels of 0.5 ng/house fly it caused excitatory symptoms immediately after intrathoracical injection. However, in mice injections of 0.03 mg of the toxin intracerebroventricularly resulted in no apparent symptoms of intoxication. These results demonstrate that Tx4(6-1) of P. nigriventer has no toxicity for mice, and suggest that it is a specific anti-insect toxin. The mol. wt (5244.6) and purity of the toxin were determined by desorption mass spectroscopy. The complete amino acid sequence of this toxin was established by direct automated Edman degradation and manual 4-N,N'-dimethylaminoazobenzene-4'isothiocyanate/phenyl-isothiocyanate microsequence analyses of peptides obtained from digests with various proteases. The protein contains 48 amino acids including 10 Cys and 6 Lys. The N-terminal and C-terminal residues were Cys. The Tx4(6-1) sequence differs from that of previously characterized neurotoxins found in the same and other venom spiders, but exhibited sequence similarities in the location of the Cys residues.
Collapse
Affiliation(s)
- S G Figueiredo
- Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | | | | |
Collapse
|
48
|
Saccomano NA, Ahlijanian MK. Ca2+ channel toxins: Tools to study channel structure and function. Drug Dev Res 1994. [DOI: 10.1002/ddr.430330312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
49
|
Quistad G, Skinner W. Isolation and sequencing of insecticidal peptides from the primitive hunting spider, Plectreurys tristis (Simon). J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)78096-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
50
|
Neurotoxic acylpolyamines from spider venoms. J Chem Ecol 1993; 19:2411-51. [DOI: 10.1007/bf00979674] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/1993] [Accepted: 05/05/1993] [Indexed: 11/26/2022]
|